Shoe stiffener



The subject oi. this invention is shoe stitlern ers, by which is meant more specifically shoe parts of the character of box toes or counters.

in order to minimize the undesirable efie ct or the relatively thick and rigid edges of such still'eners alter their incorporation into shoes, has been the custom to shire the marginal portions of such stitleners sothat they diminish gradually in thickness to a feather edge, which is intended to merge imperceptibly with the shoe upper material. In fine shoeinalring, however, especially where upper material such as leather of considerable elasticity is lasted by modern methods conducive to maximum stretching of such upper material, the removal of the last lrom the shoe is inevitably accorn anied by contraction of the upper materia, particularly in. those areas which lack a backing or support of stiliener material. Thus, contraction of the upper material brings the relatively rigid -r ot a stitt'ener to bear sutficiently against h upper material to raise a prominent ridge herein, which not only detracts from the appearance and salability of the shoe, but whose prominence and hence ungainliness, paradox- -.ically though it may seen, are greater the liner the lasting. 4

accordance with the present invention, doaway with the foregoing dihlculties by rendering the marginal portions of shoe stit- Iteners permanently and suificiently limp so they yield or recede readily under the contraction of the upper material, rather than unsightly ridges therein. l have -Bound that the desired limpness may be narted to the marginal portions by treating them, preferably alter striving, with an agent whichtransforms the stifiener material and the fibrous foundation in which it is carried to a permanently limp or plastic condition.

iVhile not limited thereto, l shall new deal more specifically with the application my invention to three classes of box toes which are used widely in shoemalring. All these classes or" box toes have the common feature that they consist of a fibrous toundation, such as felt or other fabric, impregnated with a material which acts to stillen the ltoimdation markedly. They also have the .llpplieatlon area ftroreinber common capability oi being made temporarily limp by a suitable treatment in order to be comformable to the Sl'lEtPQOl the last, and of then hardening stifl'ening in place in the shoe. One class of hen toes contains pyronylin or celluloid as the stifiening agent. To the slriyed marginal portions of such stifieners, I apply plasticizing agents such as dibutyl pthallate, tetraethylene glycol monoethyl ether, tri ethyl-amine, tri-cresyl--phos phate, ethyl lactate, castor oil, or rape seed oil, which keep the marginal portions permanently limp. The treatment of this class of stifieners with volatile solvents of the yroxylin or celluloid type to make the stideners temporarily limp does not significantly afiect the permanent limpness of the manginal portions, because of the greater affinity of the plasticizing agentfor the fibrous toundation than for the volatile solvent. Another class of box toes contains starch, glue, or kindred water-soluble materials as the stifiening agent. ll treat the skived rniarainal portions of such stifienerswith plasticizing agents such as glycerine or til-ethanol amine. In such case, too, the plasticieing agents have greater atfinity tor the fibrous foundation than for the water with which the still'eners are temporarily softened or rendered limp, so that the treated, shined ma-r inal portions stay limp indefinitely Still another class of tifileners are associated with thermoplastic materials such as normally solid waxes and gums. ll employ netroleurn or other oils in such case as the permanent plasticizers for the skived marginal portions, the oils being retained suficiently by the fibrous foundation during the usual heat-treatment to which the stiffeners are subjected to preserve the desired limpness of the marginal port-ions after the main portions have cooled and become stid in the shoe.

ln speaking hereinhetore about the permanent linipness imparted to the marginal portions-of shoe stifieners, 1 mean a limpness which endures not only throughout the shoe-- making operations, including the pulling oi the lasts, and the completion oi the shoes, but which persists for a sut iciently long peall riod thereafter that there is no tendency to plastic stitiening a cut, said box toe being form ridges in the shoe uppers by reason of skived at a margina portion and containing rigidit or stiffness in the edges of the stiifenonly at said portion an agent which renders it ers and the contraction of the upper material permanently limp. 5 thereagainst. My invention has the impor- In testimony whereof I have afixed my sig 7O taut advantage that it does away with the nature. past necessity of guarding carefully against STANLEY P. LOWELL. inequalities or irregularities occurrlng m the skiving of the marginal portions of the stiff- 10 eners, as freedom from r1dges in the shoe upper does not depend as heretofore upon perfect skiving.

The principles of the present invention extend to situations where it is desired to render shoe stifieners permanently limp in localities 8O other than their marginal areas, although, as has been described in greater detail, they have valuable application in doing away with the undesirable efl'ect heretofore produced on my shoe uppers by the marginal portions of shoe stifi'eners, especially when shoe manufacturing involves lasting methods conducive to maximum stretching of the shoe upper.

I claim: 1. A shoe stiffener of substantially uniform thickness throughout and substantially uniformly impregnated with a stifi'ening agent but having a only localized portion in permanently limp condition. 3g 2. A shoe stiifener of substantially uniform Q5 thickness throughout and substantially uniformly impregnated with a stifiening agent but having only a marginal portion in perxnanently limp condition.

5 3. A shoe stiffener of substantially uniform my thickness throughout and substantially uniformly impregnated with a stifi'ening agent but having only a skived marginal portion in permanently lim condition. so 4, A shoe sti ener of substantially unia form thickness throughout, consisting of a fibrous foundation impregnated substantially uniformly throughout with a stiffening agent but in permanently plasticized condi- 5 time only at a marginal portion. I

5. A shoe stiflener of substantiall uniform thickness throughout consisting o a fibrous foundation skived at a marginal portion and impregnated substantially uniformly so throughout with a stifi'ening agent but in per- 1 1 manently plasticized condition only at said marginal portion.

6. A box toe consisting of a fibrous foundation impregnated throughout with pyroxylin,

said box toe being skived at a marginal porm,

tion and containing only at said portion an agent which renders it permanently limp.

7. A box toe consisting of a fibrous foundation impre ated throughout with a water so soluble sti ening agent, said box toe being 3% skived at a marginal portion and containing only at said portion an agent which renders it permanently limp. 8. A box tie consisting of a fibrous founda-= $5 tion impregnated throughout with a therrnm 18a 

